Retractable knife



FIG. 1 is a perspective view of a retractable knife showing my new design;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a rear elevational view thereof;

FIG. 4 is a left side elevational view thereof;

FIG. 5 is a right side elevational view thereof;

FIG. 6 is a top plan view thereof;

FIG. 7 is a bottom plan view thereof;

FIG. 8 is a front elevational view of the retractable knife when the blade is received in the handle portion;

FIG. 9 is a rear elevational view of the retractable knife when the blade is received in the handle portion;

FIG. 10 is a left side elevational view of the retractable knife when the blade is received in the handle portion;

FIG. 11 is a right side elevational view of the retractable knife when the blade is received in the handle portion;

FIG. 12 is a top plan view of the retractable knife when the blade is received in the handle portion; and,

FIG. 13 is a bottom plan view of the retractable knife when the blade is received in the handle portion. 

CLAIM The ornamental design for a retractable knife, as shown and described. 